The following method and apparatus have been proposed so far in U.S. Pat. No. 4,813,000: a method and an apparatus for storing color data showing the hue, chroma, and lightness of a selected color to be toned by using a portable color meter, connecting the color data in the color meter to a computer, storing a plurality of usable paint blends in the computer, storing color data showing the hue, chroma, and lightness of each paint designated by the stored usable color formula in the computer, comparing the color data for a selected color received from the color meter with the stored color data showing each of the stored usable color blends to find most similar matching, selecting a stored paint blend shown by the color data found as the most similar matching, and thereby color-matching the selected color (refer to U.S. Pat. No. 4,813,000).
In recent years, the number of paint colors having brilliant feeling in which aluminum powder and brilliant mica powder are blended has been increased for paint colors of vehicles because personal tastes have been diversified and the aesthetic dress design has been advanced. To tone the paint colors having brilliant feeling, the color-matching method disclosed in the above U.S. Pat. No. 4,813,000 is not sufficient in toning accuracy.
U.S. Pat. No. 6,362,885 discloses a metallic-pearl-paint color-matching method for obtaining a blending quantity of a coloring material and a brilliant material coinciding with a target color of a metallic-pearl paint obtained by blending a coloring material and brilliant material, in which a proper blending ratio of a coloring material and a brilliant material is obtained by previously measuring spectral reflectances of a plurality of coated plate samples obtained by changing blending ratios of a coloring material and brilliant material to be used by a variation-angle spectrophotometer, storing the spectral reflectances in a memory of a computer, and estimating reproduced spectral reflectances while capturing a change of variation-angle spectral reflectances caused by changing quantities of a brilliant material to be added when performing toning by using the measured spectral reflectances (refer to U.S. Pat. No. 6,362,885).
In the case of this method, however, at least 5 to 6 levels of coated plate samples obtained by changing quantities of a brilliant material to be blended or blend ratios of a coloring material and the brilliant material are necessary for one color material and a lot of labor is required to prepare basic data, and because a calculation algorithm is complex, the cost of an apparatus to be used increases.
The following are entered in U.S. patent application Publication No. 2001/036309: (A) a calorimeter, (B) micro brilliant feeling measuring instrument, and (C) a plurality of paint blends, color data and micro brilliant feeling data corresponding to each paint blend, and color characteristic data for a plurality of elementary color paints and micro brilliant feeling characteristic data and moreover, the following method is disclosed: a toning method using a computer toning apparatus for paints constituted by the paint blends and a computer in which a color-matching calculation logic using the data for the paint blends and capable of corresponding to a paint having brilliant feeling (refer to U.S. patent application Publication No. 2001/036309). However, because very much labor and cost are required to enter color data corresponding to various paint blends used of this method, micro brilliant feeling data, color characteristic data for a plurality of elementary colors, and micro brilliant feeling characteristic data and the calculation algorithm is complex, the above mentioned causes the cost of an apparatus used to increase.
Moreover, Japanese Patent Laid-Open No. 2001-50891 discloses a liquid color measuring method for color-measuring a coloring liquid packed into a cell, in which a color is measured while continuously renewing the coloring liquid at a measuring portion of the cell by discharging and circulating the coloring liquid to and through a face including the measuring portion of the cell (refer to Japanese Patent Laid-Open No. 2001-50891). However, very much labor and cost are required to enter the color data corresponding to blends of paints having brilliant feeling used for this method and color characteristic data for a plurality of elementary color paints and moreover, it is necessary to discharge and circulate a coloring liquid to and through a face including a measuring portion of a cell. Therefore, the above mentioned causes the cost of an apparatus used to increase.
The following are prior-art document information relating to the invention of this application.
U.S. Pat. No. 4,813,000
U.S. Pat. No. 6,362,885
U.S. patent application Publication No. 2001/036309
Japanese Patent Laid-Open No. 2001-50891
The above both methods disclosed in U.S. Pat. No. 6,362,885 and U.S. patent application Publication No. 2001/036309 respectively have problems that when toning a paint having brilliant feeling, it is necessary to perform toning while checking the optical characteristic of a paint film including a brilliant material even in repetitive toning in which the basic blend of a paint is already known and moreover because brilliant feeling is included as a factor in addition to colors, toning becomes complex, the toning frequency until reaching a shipment pass level increases, and the number of man-hours for preparing coated plates for toning is increased.
Moreover, in the case of the method disclosed in Japanese Patent Laid-Open No. 2001-50891, though it is unnecessary to prepare coated plates for toning when toning a paint having brilliant feeling, it is impossible to completely tone a paint containing a brilliant material such as a paint having brilliant feeling whose effect cannot be confirmed before coated plates are prepared (e.g. paint blended with micro titanium) or a paint color having much less scattering factors.
It is an object of the present invention to provide a color-matching method capable of easily and accurately toning a paint whose basic blend is already known and has brilliant feeling and contributing to reduction of the toning frequency before reaching a shipment pass level.